128330121 has 4 divisors (see below), whose sum is σ = 171106832. Its totient is φ = 85553412.

The previous prime is 128330117. The next prime is 128330141. The reversal of 128330121 is 121033821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 128330121 - 2² = 128330117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128330101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21388351 + ... + 21388356.

It is an arithmetic number, because the mean of its divisors is an integer number (42776708).

Almost surely, 2^128330121 is an apocalyptic number.

It is an amenable number.

128330121 is a deficient number, since it is larger than the sum of its proper divisors (42776711).

128330121 is an equidigital number, since it uses as much as digits as its factorization.

128330121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42776710.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 128330121 is about 11328.2885291645. The cubic root of 128330121 is about 504.4013046877.

Adding to 128330121 its reverse (121033821), we get a palindrome (249363942).

The spelling of 128330121 in words is "one hundred twenty-eight million, three hundred thirty thousand, one hundred twenty-one".